1. Field of the Invention
The present invention relates to an endoscope system inserted into a human body.
2. Description of the Related Art
Endoscopes are known for inserting thereof into human cavities to inspect alimentary canal. In order to inspect the inside of human cavities, an endoscope has a flexible insertion section and a charge-coupled-device formed on a distal end of the insertion section. A channel penetrates through a proximal end and distal end of the endoscope so that the distal end is inside the human cavities and the proximal end is outside the human cavities. Various treatments can be conducted by inserting instruments, e.g., a pair of forceps into the channel.
Endoscope systems are under development in which instruments are extended and retracted by several pairs of rollers, driven by electricity, which are disposed in the endoscope (refer to Japanese Unexamined Patent Application, First Publication No. S57-117823, for example). According to this type of endoscope systems, an instrument is supported by the circumference of a pair of rotative drums driven by micro-motors which are provided in the endoscope. The instrument supported between the drums can be extended from the channel and retracted into the channel by operating, i.e., rotating the drums electrically by operating the micro-motors in predetermined directions.